A food-ingested sublethal concentration of thiamethoxam has harmful effects on the stingless bee Melipona scutellaris

Author(s)

Miotelo, Lucas ^[1] ; Mendes dos Reis, Ana Luiza ^[1] ; Rosa-Fontana, Annelise ^[1] ; da Silva Pachu, Jessica Karina ^[2] ; Malaquias, Jose Bruno ^{[3, 4]} ; Malaspina, Osmar ^[1] ; Roat, Thaisa Cristina ^[1]

Affiliation

^[1] Sao Paulo State Univ UNESP, Inst Biosci, Dept Gen & Appl Biol, Rio Claro, SP - Brazil

^[2] Luiz de Queiroz Coll Agr ESALQ, Dept Entomol & Acarol, BR-13418900 Piracicaba, SP - Brazil

^[3] Sao Paulo State Univ UNESP, Inst Biosci, Dept Biostat, BR-18618693 Botucatu, SP - Brazil

^[4] Sao Paulo State Univ UNESP, IBB, BR-18618693 Botucatu, SP - Brazil

• Document type: Journal article
• Source: Chemosphere; v. 288, n. 1 FEB 2022.
• Web of Science Citations: 0

Abstract

In recent years, the importance of bee's biodiversity in the Neotropical region has been evidencing the relevance of including native bees in risk assessments. Therefore, the sublethal effects of the insecticide thiamethoxam on the survival and morphological parameters of the stingless bee Melipona scutellaris were investigated in the present study. Cells from both non-target organs (Malpighian tubules and midgut) and target organs (brain) were analyzed for morphological alterations using light microscopy and transmission electron microscopy. The findings showed that when M. scutellaris foragers were exposed to a sublethal concentration of thiamethoxam (LC50/100 = 0.000543 ng a. i./mu L), longevity was not reduced but brain function was affected, even with the non-target organs attempting to detoxify. The cellular damage in all the organs was mostly reflected in irregular nuclei shape and condensed chromatin, indicating cell death. The most frequent impairments in the Malpighian tubules were loss of microvilli, disorganization of the basal labyrinth, and cytoplasmic loss. These characteristics are related to an attempt by the cells to increase the excretion process, probably because of the high number of toxic molecules that reach the Malpighian tubules and need to be secreted. In general, damages that compromise the absorption of nutrients, excretion, memory, and learning processes, which are essential for the survival of M. scutellaris, were found. The present results also fill in gaps on how these bees respond to thiamethoxam exposure and will be useful in future risk assessments for the conservation of bee biodiversity. (AU)

• FAPESP's process: 17/21097-3 - Bee-agriculture interactions: perspectives to sustainable use
• Grantee: Osmar Malaspina
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 18/20435-5 - Modeling with game theory of behavioral / adaptive strategies of Spodoptera frugiperda and Helicoverpa armigera in Bt crops with spatio-temporal co-occurrence
• Grantee: José Bruno Malaquias
• Support Opportunities: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 15/20380-8 - Ecological modelling of the larval dispersion of Spodoptera frugiperda (Lepidoptera: Noctuidae) on Bt cotton: implications for evolution and resistance management
• Grantee: José Bruno Malaquias
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/05953-7 - Ecological Modeling of the Resistance Evolution of Spodoptera frugiperda on Bt Cotton Mediated by Seed Contamination and Temperature Increasing
• Grantee: José Bruno Malaquias
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 20/03527-3 - Differential gene expression of Melipona scutellaris Malpighi tubule transcriptomes exposed to thiamethoxam
• Grantee: Lucas Miotelo
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 12/13370-8 - How is the reaction of the Apis mellifera brain to a sublethal dose of thiamethoxam?
• Grantee: Thaisa Cristina Roat
• Support Opportunities: Research Grants - Young Investigators Grants